The proposed research project will investigate sexual minority health disparities during the transition from adolescence to young adulthood. The Healthy People 2010 (NCHS 2000) initiative identifies sexual minorities as a key population of interest regarding health disparities, and an emerging field of research is beginning to document these inequalities. These health disparities include many "key national indicators of well-being" identified by NICHD (2008). The existing research on sexual minorities, however, has several limitations: 1) it is largely based on clinical and community samples;2) it relies on cross sectional data sets;3) it is often limited to one dichotomous indicator of sexual orientation;4) it often ignores environmental influences, and 5) it has examined only a small number of health related outcomes. Given these limitations, this research is poised to make important contributions to the existing literature as well as public policy but improving upon the existing data, methods, and frameworks utilized. Specifically, this research will utilize nationally representative, longitudinal data and several indicators of same-sex orientation to investigate a wide variety of health outcomes including suicidal ideation, depressive symptoms, self-reported health, self-reported morbidities, and a series of biomarkers designed to measure anthropometric, cardiovascular, metabolic, and inflammation functioning. In addition to using these cutting-edge data, we will employ a series of innovative statistical techniques including generalized linear models, propensity score matching, multi-level models, and latent curve models. Critically, this work will employ an interdisciplinary, "ecosocial" framework that stresses the synergistic impact of individual, environmental, and biological level processes on health. Preliminary analyses conducted by the authors provide compelling evidence that the timing and patterns of sexual minority status identification are important pathways through which health outcomes are shaped. This research will build upon these preliminary findings and directly address the criticisms of previous work from an interdisciplinary framework that incorporates social, psychological, and biological processes. PUBLIC HEALTH RELEVANCE: This proposal specifically addresses a target population and goals identified by the Healthy People 2010 initiative (NCHS 2000) and will document previously unexplored longitudinal trends in sexual minority health from an "ecosocial" framework. The study of sexual minority status and health provides a unique opportunity to examine disparities among a vulnerable population distributed across all race/ethnic and socioeconomic groups, allowing us to examine health trajectories in a variety of contexts. This research will generate important findings for public health policy by identifying both positive and negative pathways through which the relationship between sexual minority status and health are mediated.